Yes, so I can see how it can be hard for a small shop owner or a family restaurant to update their menus every time. But telecom vendor has these all implemented in their billing system anyway, and if there's a company that wouldn't have problem with either technical aspects nor budget to make their site show true price, that company is Google. They totally could do it if they wanted, they just prefer to post misleading prices because people allow them to get away with it.